Fused plug means



Aug. 3, 1965 P. c. sAvocA ETAL FUSED PLUG MEANS Filed Oct. 3l. 1961 s 2 n 4 3 ew. o

Q 4 2 B l m l MM s A T l Pm I .I fo a 7 G 4% am @un 22 2 M ATTORNEYS United States Patent O 3,198,912 FUSE@ PLUG MEANS Paul f1. Savoca, Brooklyn, NX., and Anthony B.

li'arasco, Norwalk, Conn., assignors to I. il. Nottinghan il Co., lne., New York, NX., a corporation of New York Filed Get. 51, 196i, Ser. No. 149,638 1 Claim. (Cl. Zilli-115.5)

rl`he present invention relates to a fused plug connector, and more particularly to a fused plug connector that may be used in heavy duty installations, although it is apparent it will have many other uses.

In accordance with the present invention, a fused electrical plug connector is provided that is preferably made of molded material and is provided with cavities therein which house removable fuses. rlhe entire Astructure is of rugged construction so that the plug connector may be abused more than usual without any deleterious effects th reon, and without causing the fuse members embodied therein to come loose and break the electrical circuit, so that the plug connector requires no servicing unless a fuse is actually blown.

It is another object of the present invention to provide a rugged molded plug connector provided with rigid housing members formed integral therewith and so embodied in the plug connector that the only parts detachable from it are the replaceable fuses and the prong members which are adapted to be inserted Within an electrical socket or the like.

It is another object of the present invention to provide a heavy duty plug connector having replaceable fuse members disposed therein with means for maintaining the fuse members in a fixed position therein so as to complete the electrical circuit, whether the plug is accidentally dropped or abused in any manner so that the fuses maintain their proper position and do not inadvertently become loosened to cause a break in the electrical circuit in which the plug connector is disposed.

it is another object of the present invention to provide novel retaining means for a plug connector having replaceable fuse members disposed therein.

It is a further object of the present invention to provide rugged prong members detachably connected to a molded plug connector, which prong members are well insulated and yet can be easily removed from the connector when it is necessary to service the fuse members disposed therein.

ls is yet another object of the present invention to provide a plug connector having replaceable fuse members incorporated therein in which the electrical conductors are rigidly connected to one end of the housing of the fuse members, and in which retainer means are disposed in the opposite end of the fuse member housing so that the fuse members are retained therein in a predetermined position so that the electrical circuit is always completed unless a fuse is actually blown and needs replacement.

Various other objects and advantages of the present invention will be readily apparent from the following detailed description when considered in connection with the accompanying drawing forming a part thereof, and in which:

FlG. 1 is a perspective View of the fuse plug connector of the present invention and an electrical cord;

FIG. 2 is a section taken along lines 2-2 of FlG. l;

FIG. 3 is an exploded perspective view of a modified form of the invention;

FlG. 4 is an exploded perspective view of still another modification of the invention; and

ice

FIG. 5 is a vertical section of the embodiment of the invention shown in FIG. 4.

Referring to the drawings the reference numeral 10 generally designates a molded electrical plug connector. The plug connector is preferably molded from rubber, although it may also be molded from plastic materials, such as vinyl or the like.

The molded plug connector comprises a cylindrical plug member 11 provided with an enlarged rear or back end forming a flange 12 therein. The portion of the plug beyond flange 12 consists of an elongated reduced section 13 having a plurality of spaced annular recesses 14 therein forming a plurality of ribs 15 therebetween to enable a person to readily grasp the plug to insert it into or pull it out of an electrical outlet or socket. The lower end of elongate section 13 tapers down as at 16 and blends into or terminates in a molded rubber electrical cord 17. Disposed within section 13 and cord 17 are two similar electrical leads, wires or conductors 18 completely enclosed in a sheathing, covering or insulating jacket 19, as best seen in FIG. 2. The electrical conductors 18 consist of a plurality of small wires formed into an electrical conductor or cable. The upper or outer ends of a portion of the conductors 13 and cover members 19 are molded in to the plug 11, and extend into the plug beyond the iiange 12 thereon as shown in FIG. 2.

The outer or front end 21 of the molded plug is provided with two spaced elongated parallel cylindrical cavities 22 therein for receiving replaceable fuses 23 therein and fuse housings 24. The outer or front ends of cavities 22 are enlarged as indicated at 2S so as to provide a countersink therein. The fuse housing 24 comprises a cylindrical non-conducting or insulated section 26 with a circular bottom conductor plate 27 having a short sleeve or neck 2S extending thereabove. The lowed edge of housing 26 seats on the peripheral portion of plate 27, and neck 28 extends into section 26 as shown in FIG. 2, and section 25 is permanently secured or fixed to bottom plate 27 by swaging it thereon, or by the use of an adhesive, such as cement or other similar means. The upper or outer end of section 26 is provided with an internally threaded cover member 30 made of conductive material having an annnular flange 31 thereon. The upper end of section 26 is also permanently secured to member 30 by swaging or pressing member 30 into the open end of section 26 until flange 31 is disposed on the upper edge or rim of 26.

The bottom plate 27 of the fuse housing has a tubular sleeve member 33 made of conductive material extending through neck 28 and fixed thereto with a turned-over rim 34 thereon adjacent the inner end of neck 28. The tubular member 33 extends beyond or below the bottom of plate 27 and has the individual strands of wire forming the electrical conductor 18 inserted therein. The outer end of tubular member 33 is crimped or deformed inwardly as seen in FIG. 2 so as to iirmly grip and secure the electrical conductors thereto. If desired, tubular sleeve member 33 may be formed integral with the member 27.

The fuse housing 26 and its end members 27 and 3i) and tubular sleeve member 33 are preformed into a single unit or assembly before the fuse housing is molded into f Male electrical prongs are provided for detachable connection to the plug, and more particularly for threaded engagement with the threaded members Sti of the fuse housing. rThe prongs 4% are solid cylindrical members of conductive material having outer end or portion 41 of reduced diameter. The middle section oi the prongs is provided with a hexagonally shaped nut portion thereon for receiving a wrench or other tool to securely thread the prongs into members 30. The lower ends of the prongs have an enlarged cylindrical portion 43 with a flange d4 thereon. The ends of the prongs adjacent llange 44 are provided with an externally threaded sleeve depending therefrom having a cylindrical recess 46 therein in which is disposed a compression spring 47. ri`he lower or outer end oi spring 47 is provided with a cup 43 which lits over the end of the spring 47 and is slidably received within the outer end ot recess 46 as shown in FiG. 2. The portion 43 and flange portion 44 oi the prong member are covered with molded rubber or material identical to that from which the molded plug l1. is made. The prong lll is threaded into the countersinlt until it abuts the annular rim 3l of member 35i so that the threaded sleeve engages the internally threaded member 30 as clearly seen in FlG. 2. The spring member 47 causes the cup 4 to contact the end oi the elec rical fuse 23 to thereby provide an electrical path for current through the prong member, spring, cup and fuse to the bare portion electrical conductor 1d, through the lower end of fuse 23 which is in contact with tubular mem er 33.

The provision ot the prong member securely threaded home in member 3u oi the fuse housing causes the spring 47 to exert a force against the fuse to lreep the fuse positioned in its housing in contact with the electrical conductor 13 in a predetermined position at all times so that it will not become loosened and the electrical circuit will not be broken should the plug be vibrated, jarred, mishandled or abused in any way.

With reference to the modification ot the invention shown in FlG. 3, this structure is substantially the same as that shown in FG. 2, except that the spring member 59 comprises a volute spring member in which the individual turns or coils Si thereof are telescopically arranged with respect to one another so that the sprin(T normally tends to distend or expand its full length into a conical configuration with each coil 5i. vertically spaced from the next adjacent coil 51. lt is apparent that when the prong member 4t) is threaded into the member Sil with a fuse 23 disposed in the fuse housing member 24, the individual turns Si of the volute spring will be telescopically compressed with respect to one another and maintain the fuse 23 in its proper predetermined position in contact with the prong 40, and in contact with the tubular member 33 and conductor 13 so that the electrical circuit will not be inadvertently disconnected or broken when the plug is jarred, vibrated or mishandled.

The modication of the invention disclosed in EEG. 4 is substantially the same as that shown and described in FiG. 2, except that the upper threaded member 55 of the fuse housing 55 is provided with spaced annular rims 57 and 5S. Also, instead of having a biasing spring cooperating with the prong 4l) and the fuse housing 56, a circular metal disc member ad is provided having external threads 6l adapted to engage the internal threads 62 of the internally threaded member 55. The member 6) is provided with a slot in its upper end and an opening or aperture 65 extending therethrough adjacent the slot 64. The slot 64 permits the spacer member ou to be threaded by a tool, such as a screwdriver into the member 55 until it is threaded home against the upper end of fuse 23 to maintain member 23 in its predetermined position within the fuse housing 56 so that an electrical circuit or contact is maintained between the prong member 4t? and the electrical conductor 18.

Thus in this embodiment of the invention the fuse carridge 23 is held in place by the screw threaded cap me r.-

ber o@ and the prong r -amber tb is threaded home against the outer or top side do of the screw threaded cap. it will be noted that with this embodiment of the invention, the thickness of the screw threaded cap may be varied or, in other words, caps or" different size may be inserted into member 55 so 'that ditlerent size fuse cartridges 23 may be readily inserted Within the plug member as desired, and said cap will compensate for variations in the fuse lengths to maintain an electrical ilow path for current flowing therethrough. lt is also apparent that with the use oi this cap, there is provided a relatively rugged solid plug connector for use with an electrical cord and the like which can stand heavy duty usage without causing any dtmagc thereto,

inasmuch as various changes may be made in the form, location and relative arrangement of the several parts witnout departing from the essential characteristics ot the invention, it will be understood that tr e invention is not to be limited except by the scope or" the appended claim.

Ve claim:

A fused electrical connector comprising a molded plug member formed of electrical insulating material, the outer end of said plug member being provided with a pair of spaced elongated parallel cylindrical cavities, the outer ends of said cavities having a countersunk portion, a pair of fuse housings each including a substantially cylindrical electrical non-conducting central portion, each of said housing having a substantially circular bottom plate formed of electrical conducting material at the lower ends thereof, an internally threaded cover member being secured to the upper portion oi each of said housings, and being formed oi electrical conducting material, a tubular sleeve member formed of electrically conductive material, said bottom conductor plates each having a central opening formed therethrough and the central portions of said fuse housings having a bore formed therethrough, each oi said tubular sleeve members extending through the opening in one of said bottom conductor plates, each of said tubular sleeve members being adapted to be electrically connected with the terminal end of an electrical conductor, said fuse housings along with the bottom conductor plates and cover members secured thereto all being embedded into said plug member, a portion of said cover members being seated in the countersunk portion ot the associated cavities, a pair of electrical prongs, said prongs including outwardly extending cylindrical portions of electrically conductive material, the lower ends of said prongs having an externally threaded sleeve depending therefrom for threading within the threaded cover members, an elongated fuse member slidably tted within the bore through the center portion of each of said housings, retainer means disposed between and in contact with the lower portion of each of said prongs and the upper portion of one of said fuse members, each of said prongs including an enlarge flange portion covered with electrical insulating material and adapted to be received within the outer end of one oi said cavities when the prong member is threaded into operative position.

References Cited by the Examiner UNlTED STATES PATENTS ROBERT K. SCFLAEFER, Acting Primary Examiner.

BERNARD A. GLHEANY, Examiner'. 

